Intramuscular olanzapine in the management of acute agitation

To review the current efficacy and safety evidence for the use of intramuscular olanzapine in the management of acute agitation.

MEDLINE, EMBASE, and PubMed (all to March 2004) were searched for full-text, English-language publications in humans. Search terms included olanzapine, psychosis, agitation, psychiatric emergency, and intramuscular.

Prospective, randomized, controlled trials that evaluated efficacy or safety endpoints of intramuscular olanzapine in the management of acute agitation were included. All studies were evaluated independently by both authors. For clinical outcomes (efficacy, safety), the definitions as specified by each study were used.

Four prospective trials were included in this review. Intramuscular olanzapine is comparable to haloperidol or lorazepam monotherapy in managing acute agitation associated with schizophrenia and dementia. Intramuscular olanzapine is superior to lorazepam monotherapy in the management of agitation associated with bipolar affective disorder. Preliminary evidence demonstrates that intramuscular olanzapine is associated with fewer adverse movement disorders than monotherapy with intramuscular haloperidol. Interpretation of published evidence is limited by confounding factors of comparator regimens and the patient populations studied.

Additional studies comparing intramuscular olanzapine with combination antipsychotic/benzodiazepine therapy in more severely ill patients and patients with concomitant medical illnesses are needed to determine the most effective dosing regimen, use of adjunctive medications, and to obtain a comprehensive safety profile.